If we postpone unification problems, it's not necessarily at the top
level of a term, but then if we retry and find we need to insert a
'Delay' or 'Force' then it had better be at the top level or we'll get
an incorrect term. So, keep track of this in postponed constraints.
For example, delayed elaborators. If it resolves one, and it's not a
complete solution, we might end up with unsolved holes. Or - possibly
worse - we might end up with an error in a program that is silently
fixed rather than reported!
Fixes#223
On some systems "/usr/bin" and "/usr/local/bin" are not used.
If CHEZ env variable is not defined, lookup for chez in the PATH if
defined. Otherwise falls back to the old behaviour. (ie. lookup in
"/usr/bin" and "/usr/local/bin" as a last resort)
These can give valuable information, but since they're not well typed,
we have to rebuild as close an approximation as we can before passing it
to the case tree compiler. We can do this in a type-directed way, but
ignoring whether any of the arguments are convertible, and not trying to
solve any of the implicits. If this fails, it doesn't use the impossible
case, otherwise it uses it to find the missing cases in the resulting
case tree.
This looks for an .ipkg file in a parent directory before loading the
given file, and loads it relative to the .ipkg's source directory, with
the options specified in the .ipkg.
The intention is to save all the editor modes having to do the same
thing, and especially makes it possible for the new vim mode to work
with ipkgs.
If the name is given (rather than, say, computed) update it so that it's
the data type name being defined - so ambiguities are resolved
immediately. Fixes#192
Pass through the types of the interface parameters to the top level
method types, because there might be information in there that we can't
otherwise infer. Fixes#188
This means we can say 'let x = foo' and have foo not be applied to its
implicit arguments, meaning that 'x' can be instantiated at whatever
implicits it needs through the scope.
This prevents display of shadowed names from case blocks/where clauses
that are now unusable. It does mean that constraint arguments aren't
displayed, unless given an explicit name - this may not be good, since
we might want to know which constraints are in scope, so it may yet need
a little tweaking.
This is a little bit of a hack, but is for the situation where a case
block arises from the same bit of source but with a different name,
which would happen when elaborating interfaces with cases in a method
signature. If it's the same function with the same scrutinee, it's
convertible.
Fixes#191
This needed a bit of reorganisation, but it speeds up checking if a
module doesn't need rebuilding due to the import interfaces not
changing. Also it means that the "Type checking foo.idr" message is
displayed before parsing rather than after, which is probably better.
We've been generalising inferred function types to have multiplicity
RigW but sometimes (especially on lambdas) we need to infer the precise
type, so make a distinction.
This is pretty ugly, really. It would be better to be able to postpone
the choice until we know more, but it's not obvious to me how to achieve
that with the way unification is currently set up. The present way at
least works fine with code that doesn't use linearity, which is the
right default I think!
Now only abstracts over the environment once and deals with 'where'
clauses by rewriting the nested name with the rearranged environment. As
a result, it interacts far better with local definitions (i.e. where
blocks).
Always infer a multiplicity of W. Since we can pass a linear function to
one which expects an unrestricted argument, this gives the more general
result if the multiplicity is otherwise unknown.
This makes things like 'maybe id (+) x y' type check again even in the
presence of an 'id' which is declared linear!
This is the same as %auto_implicits in Idris 1, but with a more
appropriate name, because auto implicits are something else.
'%unbound_implicits off' turns off implicit forall bindings. See test
basic033 for an example.
In a small change from Idris 1, this lifts to the nearest binder or
block, so doesn't lift past an explicit "do" in particular. Blocks are:
- case branches
- if branches
- scope of local function definitions, or any binder
- do blocks
It's a big patch, but the summary is that it's okay to use a pattern in
an erased position if either:
- the pattern can also be solved by unification (this is the same as
'dot patterns' for matching on non-constructor forms)
- the argument position is detaggable w.r.t. non-erased arguments, which
means we can tell which pattern it is without pattern matching
The second case, in particular, means we can still pattern match on
proof terms which turn out to be irrelevant, especially Refl.
Fixes#178
